The present invention generally relates to driving circuits for Hall motors using Hall elements, and more particularly to a driving circuit for a Hall motor, which is capable of detecting a rotational position of a rotor of the Hall motor with high accuracy and driving the Hall motor with low power consumption.
Conventionally, as one example of a driving circuit for a Hall motor, there was a driving circuit simply designed to constantly apply or supply a constant voltage or current to Hall elements of the Hall motor. However, this conventional driving circuit is disadvantageous in that the power consumption is high because a constant voltage or current is constantly applied or supplied to the Hall elements.
On the other hand, as another example of a conventional driving circuit for a Hall motor, there was a driving circuit designed to apply or supply a pulse voltage or current having a constant period to the Hall elements of the Hall motor, regardless of the rotational period of the rotor. However, according to this conventional driving circuit, although the power consumption is lower than that of the first conventional driving circuit described above, the period of repetition with which the rotor position is detected by the Hall elements and the period of repetition with which the pulse voltage is applied does not always coincide. Accordingly, there is a disadvantage in that the sensitivity of the Hall elements is low and the accuracy with which the rotor position is detected is poor. Especially when the period of repetition of the pulse voltage is made large so as to reduce the power consumption, the accuracy with which the rotor position is detected becomes even poorer. On the other hand, if the sensitivity of the Hall elements is increased and the period of repetition of the pulse voltage is made small so as to improve the accuracy with which the rotor position is detected, the power consumption becomes high, and the low power consumption characteristic is lost.